This application is based on patent application No. 2000-319890 filed Oct. 19, 2000 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a card connector mounted on electronic devices, such as cellular phones, telephones, PDAs (personal digital assistants), portable audio devices and cameras, and more specifically to a card connector having a compact structure designed to reliably prevent an IC (integrated circuit) card from coming off.
2. Description of the Related Art
In electronic devices such as cellular phones, telephones, PDAs and cameras, a variety of functions are added by inserting an IC card with a built-in CPU or memory IC, such as a SIM (subscriber identity module) card, an MMC (multimedia card), an SD (super density) card, a Memory Stick (tradename) and a Smart Media (tradename).
To allow a removable insertion of such an IC card, the card connector has the following construction. In a connector housing of the card connector are provided a plurality of contact terminals that are connected to various signal processing circuits and a power supply circuit of an electronic device on which the card connector is mounted. The contact terminals are brought into contact with a plurality of contact pads formed on a front or back surface of the inserted IC card to electrically connect the IC card to the electronic device on which the connector is mounted.
Many of such card connectors have an eject mechanism for removing the inserted IC card from the connector.
Some of the card connectors with the eject mechanism of this kind have an elastic braking piece secured to an appropriate location in the connector housing and pressed against the card to produce a friction force acting in a direction opposite that in which the card comes off, in order to prevent the card from being pushed out rapidly and slipping off from the connector during the card ejection operation or to prevent the card from coming off the connector due to unexpected external forces during the card insertion operation.
Because the card needs to be taken out of the connector, the pressing force of the braking piece cannot be set excessively large. In a conventional card slip-off prevention mechanism using the pressing force of the braking piece, therefore, the card cannot reliably be prevented from slip-off and it easily slips off due to the causes described above or impacts.
There are growing demands in recent years on the card connector itself for smaller size, lower height and lighter weight, and therefore the card slip-off prevention mechanism needs to be reduced in size and weight.
The present invention has been accomplished under these circumstances and is intended to provide a card connector which can reliably hold the inserted card with a compact mechanism to prevent the card from slipping off.
In one aspect of the present invention, a card connector is provided for holding within a connector housing a card, formed with a recessed portion on its side surface and a plurality of contact pads on its bottom surface, in such a way that the contact pads touch contact terminals arranged in the connector housing. The card connector comprises: an eject mechanism having an eject member, the eject member moving in a card insertion direction as the card is inserted into the connector and moving in a card ejection direction to eject the card in response to a card eject operation; an elastic locking piece having a locking portion to be brought into engagement with the recessed portion of the card and a stationary portion secured to the eject member, the elastic locking piece being urged away from the card to disengage the locking portion from the recessed portion of the card when the elastic locking piece elastically recovers its original shape; and a locking piece guide means for guiding and elastically deforming the elastic locking piece to bring the locking portion into engagement with the recessed portion when the card is inserted, and for resetting the elastic locking piece from the elastic deformation to disengage the locking piece from the recessed portion when the card is ejected.
In this invention, the card is formed with the recessed portion for engagement with the locking piece, and the elastic locking piece is attached to the eject member that slides together with the card as the card is inserted or retracted. The elastic locking piece is urged away from the card so that when the elastic locking piece is elastically reset to its original shape, the locking portion is disengaged from the recessed portion of the card. The locking piece guide means guides and elastically deforms the elastic locking piece to engage the locking portion with the recessed portion when the card is inserted and, when the card is ejected, resets the elastic locking piece from the elastic deformation to disengage the locking portion from the recessed portion.
Because the present invention forcibly moves the locking portion of the elastic locking piece toward or away from the card, not according to the movement of the card itself but according to the movement of the eject member which moves similarly to the card, the locking portion of the elastic locking piece can adopt a hook-shaped locking structure that can completely restrict the movement of the card in the withdrawal direction. Further, in this invention because the elastic locking piece, when the card is locked, is pushed out and elastically deformed by the locking piece guide means, this locking structure has a stronger locking force than the conventional construction in which the elastic locking piece in an elastically reset state engages with the recess of the card when the card is locked. The locking structure of this invention can therefore prevent the card from coming off the connector inadvertently or due to unexpected external forces or impacts and thus hold the card reliably at all times during the insertion operation.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.